Storage routers allow devices, such as PCs and servers, to utilize the massive storage capability of a storage network. Access to the storage router by such devices may be provided over an IP network and may implement a predetermined physical layer protocol, such as Ethernet. The storage router may access storage devices through the storage network using another predetermined physical layer protocol. In the case of a fibre channel network, the storage router may communicate packets configured in accordance with a fibre channel protocol over the storage network. Some conventional storage systems also implement a storage protocol, such as the Small Computer Systems Interface (SCSI) protocol, for storage related communications between the servers and storage devices through the storage router. In these SCSI systems, SCSI requests, commands and responses may be encapsulated in IP/Ethernet frames for communications between the servers and the storage router. SCSI requests, commands and responses and may also be encapsulated in fibre channel protocol packets for communications between the storage router and storage (i.e., SCSI) devices.
Conventional storage routers typically employ a single/symmetric data path or channel between a particular device on the IP/Ethernet side and a device on the fibre channel/SCSI side. Many individual devices, such as servers and host systems, may wish to utilize the multiple IP/Ethernet interfaces of a storage router. Multiple interfaces may allow increased communications bandwidth between servers and a storage router and may also provide increased reliability through network redundancy. This allows datagrams to be communicated over more than one data path between multiple ports of the storage router and server. Some conventional storage routers may use a high-speed backplane to support these asymmetric data paths. One problem is that the high-speed backplane is very costly and its incorporation into storage routers significantly complicates the implementation further increasing cost and complexity and possibly reducing reliability.
Thus there is a general need for an improved storage router and method for routing datagrams. There is also a need for a storage router and method for routing datagrams within a storage router that supports asymmetric, multiple and/or redundant communication paths with host systems. There is also a need for a storage router and method for routing IP datagrams between data path processors of a storage router. There is also a need for a storage router and method for routing IP datagrams that is less costly. There is also a need for a storage router and method for routing IP datagrams that is less complex. There is also a need for a storage router and method for routing IP datagrams that is more reliable. There is also a need for an improved SCSI-based storage router and method.